Table 1 Comparison of baseline characteristics and clinical outcomes of patients with methicillin-susceptible S. aureus bacteremia who received empiric antimicrobial therapy with β-lactams or vancomycin
Patient characteristics | β-lactama (n = 131) | Vancomycina (n = 124) | p value |
|---|---|---|---|
Age (mean ± standard deviation in years) | 53.2 ± 16.5 | 59.4 ± 18.3 | 0.005 |
Males | 83 (63.4) | 86 (69.4) | 0.31 |
Community-onset | 105 (80.2) | 84 (67.8) | 0.03 |
Hospital-onset | 26 (19.8) | 40 (32.3) | 0.03 |
HIV infection | 11 (8.4) | 8 (6.5) | 0.55 |
Hepatitis C infection | 29 (22.1) | 28 (22.6) | 0.93 |
Immunocompromised | 14 (10.7) | 10 (8.1) | 0.47 |
Alcohol or illicit drug abuse | 41 (31.3) | 38 (30.6) | 0.91 |
Intravenous drug use | 29 (22.1) | 29 (23.4) | 0.81 |
Charlson comorbidity index (median with IQR) | 3 (1.0–6.0) | 4 (1.0–7.0) | 0.001 |
Pitt bacteremia score (median with IQR) | 1 (0–2) | 1 (0–2) | 0.17 |
Infectious diseases consultation | 98 (74.8) | 80 (64.5) | 0.07 |
Source of bacteremia | |||
Central or peripheral line | 20 (15.3) | 22 (17.7) | 0.62 |
Skin and soft tissue | 31 (23.7) | 16 (12.9) | 0.04 |
Intravenous drug use | 21 (16.0) | 19 (15.3) | 1.00 |
Bone or joint infection | 18 (13.7) | 10 (8.1) | 0.16 |
Lung | 4 (3.1) | 3 (2.4) | 1.00 |
Other | 12 (9.2) | 10 (8.1) | 0.83 |
Unknown | 25 (19.1) | 44 (35.5) | 0.005 |
Infective endocarditis | 24 (18.3) | 12 (9.7) | 0.05 |
Metastatic complications | 40 (30.5) | 27 (21.8) | 0.11 |
Surgical source control | 33 (25.2) | 19 (15.3) | 0.05 |
Recurrent infection at 6 months | 4 (3.1) | 4 (3.2) | 1.00 |
Empiric antimicrobials | |||
Vancomycin | 88 (67.2) | 123 (99.2) | <0.001 |
Daptomycin | 2 (1.5) | 0 | 0.50 |
Linezolid | 2 (1.5) | 0 | 0.50 |
Cloxacillin or cefazolin | 131 (100) | 0 | <0.001 |
3rd generation cephalosporin | 40 (30.5) | 0 | <0.001 |
Piperacillin–tazobactam | 33 (25.2) | 0 | <0.001 |
Ticarcillin–clavulanic acid | 3 (2.3) | 0 | 0.25 |
Carbapenem | 2 (1.5) | 0 | 0.50 |
Otherb | 47 (35.9) | 66 (53.2) | 0.01 |
Blood culture time to positivity (median hours with IQR) | 20 (16.5–24.9) | 18.3 (15.9–23.5) | 0.17 |
Duration of empiric therapy (median hours with IQR) | 54 (42.0–69.0) | 48 (29.6–75.8) | 0.28 |
Duration of definitive therapy (median days with IQR) | 31.5 (13.0–42.0) | 28 (10.0–42.0) | 0.17 |
Time to receipt of empiric therapy (median hours with IQR) | 2 (0–7) | 20.9 (4.2–28.3) | <0.001 |
Time to receipt of β-lactam (median hours with IQR) | 3 (0.2–16.3) | 68.2 (51.5–95.4) | <0.001 |
Time to receipt of cloxacillin or cefazolin (median hours with IQR) | 21.0 (4.4–31.2) | 68.3 (51.6–95.4) | <0.001 |
Primary outcome | |||
28-day mortality | 7 (5.3) | 11 (8.9) | 0.27 |
Secondary outcomes | |||
90-day mortality | 14 (10.7) | 22 (17.7) | 0.11 |
Duration of bacteremia (median hours with IQR)c | 70.7 (46.9–119) | 97.1 (61.6–148) | 0.007 |
≥3 days | 58 (50) | 72 (63.2) | 0.047 |
Hospital length of stay (median days with IQR)d | 17 (11–36) | 17 (12–36.5) | 0.84 |